However, the latter part of the launch — after the satellite
was deployed — was the moment most viewers were waiting for:
the landing of the 229-foot-tall Falcon 9 rocket's first stage on
a robotic ship at sea.

The drone ship came into view on the webcast just minutes after
the first stage separated from the rest of the rocket. The camera
show the glow of rocket thrusters on the ship's deck... Then the
feed switched off, showing only rainbow bars:

Lauren Lyons, another SpaceX webcast announcer, said "you saw
what we all saw," noting the fate of the first stage was unknown
at the time.

Why sticking a rocket landing is a huge deal

The Falcon 9 rocket is a very odd bird.

Most rockets cost tens or hundreds of millions of dollars, yet
are rendered as garbage the moment they launch. Instead of being
recycled, they crash into the ocean and sink to the bottom after
lofting a payload into orbit.

"Just
Read the Instructions," a robotic platform designed to land the
first stage of a Falcon 9 rocket.SpaceX
on Flickr

But after delivering SES-9 into space tonight, the Falcon 9
tried to
land about half of itself on a drone ship in the Atlantic
Ocean.